Qualification > Math
All Mechanics DOUBTS HERE!!!
nid404:
--- Quote from: Khey on May 04, 2010, 05:13:02 pm ---A large crate of mass 40kg lies at rest on rough horizontal ground. One end of the rope is attached to the crate and the rope makes an angle of 30 with ground as shown in the diagram. The tension of the rope is 150N and the crate is on the of moving along the plane.
By modelling the crate as a particle,
(a) Find the value of [mue], the cofficient of frction between the crate and the ground.
The rope remains at 30 degree to the ground but the tension init is increased to 200N.
(b) Find the acceleration of the crate.
--- End quote ---
a) u= F/R
F=150cos30
R=400-150sin30
u=130/325
=0.4
b) horizontal force=Tcos30=200cos30=173.3N
173-F(uR)=40a
173-130=40a
a=3.4m/s2
Saladin:
here u go.
Khey [Rainbow]:
Thanks to "nid404" and "the mysterious dude"
but both of u have differnt answers so m confused bout who's answer is right..but its alryt i will ask my teacher
once again Thanks alot ;D
nid404:
lol...ohk
i dunno....I think R= mg-150sin30
Saladin:
Mine is, I did it the Edexcel method, and if it was 3.4 ms-2, that would have been too high a speed, considering that at 150, it would not move.
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